Fix off-by-one in shape_tree_mark/shape_tree_compact
This was using < so subtract one from the last shape id would have us
miss the last inserted shape. I think this is unlikely to have caused
issues because I don't think the newest shape will ever have edges.
We do need to use - 1 because otherwise RSHAPE wraps around and
returns the root shape.
Fix off-by-one in shape_tree_mark/shape_tree_compact
This was using < so subtract one from the last shape id would have us
miss the last inserted shape. I think this is unlikely to have caused
issues because I don't think the newest shape will ever have edges.
We do need to use
- 1
because otherwise RSHAPE wraps around andreturns the root shape.